Calibrating Engineering Judgment in Geotechnical Risk Analysis

本研究利用案例研究的方法，发展了岩土工程风险分析中量化工程判断的改进方案。这一概念基于岩土工程中的四个趋同趋势：(1)主观判断被视为岩土工程实践的重要；(2)重要的组织正在使用岩土风险分析；(3)当前涉及量化专家判断的岩土风险分析趋于实用，但需要理论基础；以及(4)当前的风险分析案例研究是一个真实的实验室，以加深我们对工程判断如何量化、如何验证和校准以及所产生的风险分析的稳健性的理解。研究采用了两项关于大坝安全的主要岩土风险分析研究，以了解验证和校准专家分配的概率的过程。作为案例研究的起点，本研究运用了主观概率理论。这项研究进一步发展了这一知识体系，建立在复杂风险分析中使用岩土判断的独特方面。将所开发的方法应用于大型大坝组织承担的两个重大岩土风险分析项目。研究分为四个任务：案例研究、理论和方法开发、测试应用和信息传播。所采用的两个案例研究使用了对大型土石坝安全的广泛记录的岩土风险分析。每项研究都在很大程度上依赖于咨询专家的量化判断。该项目将历史工程案例研究与其他学科(如认知心理学、管理科学和归纳推理)的理论发展相结合，并与正在进行的项目的实际测试应用相结合。智力的价值在于将多学科的见解带到一个实际的、新兴的、关键的岩土工程实践领域。这项研究的更广泛影响将因以下几个因素而得到加强：马里兰大学提供了一个多样化的研究环境；将大力招收女性和少数族裔学生，包括研究生和本科生；工作成果将出现在本科生研究、研究生和专业课程以及大型多学科课程中；技术风险分析已渗透到各级政府的管理和监管活动中。专业判断的使用越来越多地被量化为概率，与这些风险分析的大多数使用有关，并且项目的结果可以为所有这些努力提供信息。特别是，我国民用基础设施免受自然灾害和人为威胁的安全问题已成为全国辩论的主要议题。风险分析和量化专家判断的必要作用对于我们处理这些危险和威胁的能力是不可或缺的。

This research utilizes a case-study approach to develop improved protocols for quantifying engineering judgment in geotechnical engineering risk analysis. The concept is based on four converging trends in geotechnical engineering: (1) Subjective judgment is viewed as important to geotechnical practice; (2) important organizations are using geotechnical risk analysis; (3) current geotechnical risk analyses involving quantified expert judgment tend to be practical, but a theoretical basis is needed; and (4) current risk analyses case studies are a real life laboratory for furthering our understanding of how engineering judgment is quantified, how it is validated and calibrated, and how robust the resulting risk analyses are.The research employs two major geotechnical risk analysis studies of dam safety to understand the process of validating and calibrating probabilities assigned by experts. As a starting point for the case studies, the research uses theory from subjective probability. The research furthers this body of knowledge, building on unique aspects of the use of geotechnical judgment in complex risk analyses. It applies the developed approaches in two major geotechnical risk analysis projects undertaken by large dam-owning organizations.The research is organized in four tasks: case studies, theory and method development, tested applications, and information dissemination. The two case studies employed use an extensively documented geotechnical risk analysis of the safety of large embankment dams. Each study relied heavily on the quantified judgment of consulting experts. The project integrates historical engineering case studies with theoretical developments in other disciplines (e.g., cognitive psychology, management science, and inductive reasoning), and with practical tested applications on ongoing projects. The intellectual merit consists in bring multidisciplinary insight to a practical, emerging, critical area of geotechnical engineering practice.The broader impact of the research will be enhanced by several factors: The University of Maryland provides a diverse research environment; strong efforts will be made to recruit women and minority students, both graduate and undergraduate; the outcomes of the work will appear in undergraduate research, graduate and professional courses, and in a large multi-disciplinary course; technological risk analysis has become pervasive in the management and regulatory activities of government at all levels. The use of professional judgment, increasingly quantified as probabilities, pertains to most of these uses of risk analysis, and the results of the project can inform all these endeavors. In particular, the security of our civil infrastructure against natural hazards and man-made threats has come to dominate national debate. Risk analysis and the necessary role of quantified expert judgment are integral to our ability to address these hazards and threats.